Tropical Cyclone Olga Continues to Weaken

Tropical Cyclone Olga continued to weaken on Tuesday as it moved over the South Indian Ocean north of Western Australia. At 11:00 p.m. EDT on Tuesday the center of Tropical Cyclone Olga was located at latitude 19.3°S and longitude 115.8°E which put it about 265 miles (435 km) north-northeast of the Exmouth, Australia. Olga was moving toward the south-southwest at 4 m.p.h. (6 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1003 mb.

An upper level trough over the South Indian Ocean west of Australia continued to produce strong northwesterly winds that blew toward the top of Tropical Cyclone Olga’s circulation. Those winds caused strong vertical wind shear. The strong upper level winds blew the tops off of most of the thunderstorms in Tropical Cyclone Olga. There were still a few thunderstorms in bands in the southeastern periphery of Olga’s circulation. Bands in the other parts of Tropical Cyclone Olga consisted primarily of showers and lower clouds.

The strong vertical wind shear also caused the pattern of wind speeds around Tropical Cyclone Olga to be asymmetrical. Winds to tropical storm force extended out 100 miles (160 km) in the southern half of Olga’s circulation. Winds to tropical storm force only extended out 35 miles (55 km) in the northern half of Tropical Cyclone Olga.

Tropical Cyclone Olga will move through an environment that will be unfavorable for intensification during the next 24 hours. Olga will move over water where the Sea Surface Temperatures are near 28°C. However, the upper level trough west of Australia will continue to cause strong vertical wind shear. The strong wind shear will cause Tropical Cyclone Olga to continue to weaken.

Tropical Cyclone Olga will move around the northwestern part of a high pressure system over Australia. The high pressure system will steer Olga toward the southwest during the next 24 hours. On its anticipated track, Tropical Cyclone Olga will be north of Exmouth in 24 hours.

Tropical Cyclone Olga was already bringing gusty winds to the area around Barrow Island. A weather station on Barrow Island reported a sustained wind speed of 36 m.p.h. (58 km/h) and a wind gust of 46 m.p.h. (74 km/h).